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Finding the Fourth Proportional to 863.87, 1,288.28 and 815.34

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Solution

The fourth proportional to 863.87, 1,288.28 and 815.34 is: 1,215.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    863.87 : 1,288.28 = 815.34 : x
  2. Step 2: Convert to fraction form
    863.87/1,288.28 = 815.34/x
  3. Step 3: Cross multiply
    863.87x = 1,288.28 × 815.34
  4. Step 4: Simplify right side
    863.87x = 1,050,387.17
  5. Step 5: Solve for x
    x = 1,050,387.17/863.87
  6. Step 6: Final answer
    x = 1,215.92

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.